Portable communication and computing devices such as smartphones, mobile phones, tablets etc. are compact devices which are powered from rechargeable battery sources. The compact dimensions and battery source both put severe constraints to the maximum acceptable dimensions and power consumption of transducers and transducer amplification circuit utilized in such portable devices. Hence, it is advantageous to integrate multiple functions in a single transducer unit such as a microphone. This type of integration may reduce power consumption of active circuitry, reduce space consumption and lower assembly costs of the portable communication or computing device in question. Portable communication devices furthermore often comprise a plurality of transducers such as microphones for voice and sound pick-up, recording and transmission which adds to the advantages of integrating multiple functions in a single transducer device.
Accordingly, a transducer amplification circuit that is connectable to a single broadband sound transducer and capable of amplifying and processing both audible sound signals and ultrasonic signals would be advantageous. It would further be advantageous if the transducer amplification circuit was capable of providing the audible sound signal and ultrasonic sound signal in digital formats in separate channels of a digital audio stream. This feature allow a microprocessor such as a Digital Signal Processor of the portable communication and computing devices to receive and separately process each of the sound signals for different functions in the portable communication and computing devices.